1. Field of the Invention
The present invention relates to a detection system/method using a radar apparatus for displaying searched surrounding conditions. More particularly it relates to a radar apparatus for enlarging an area around chosen targets and modifying the display for target motion.
2. Background Information
Conventionally, a zoom function is used in radar apparatus, allowing an operator to enlarge a desired portion of a whole radar coverage for observing smaller details within a particular area of interest.
A commonly used technique in this kind of zoom function is to place a cross-hair cursor (a pair of intersecting lines for specifying a particular location on a screen) at the center of an area to be zoomed and operate a key to execute the zoom function, whereby an enlarged image of the area around the cursor position is presented on the screen at a varied range scale., Although such a function is effective in order to preponderantly supervise the predetermined range, it is difficult to grasp the relationship of the relative position of the enlarged range and image in the whole detection area, since the whole contents of a display are changed before and after performing a zoom function.
The applicant of the present invention has filed the Japanese Unexamined Patent Publication No. 9-49874(1997)[Tokuganhei 9-49874], in which a radar apparatus was disclosed having a plurality of display windows independently to display the whole surveillance area or some part of the display on multiple divisions of the monitor screen respectively.
Inevitably it is necessary to specify which area to enlarge ( e.g., by a trackball etc.), since the function to perform the enlarging display of the predetermined range to the part in a display screen is commonly used in order to indicate and supervise the target, which exists in a radar range, by enlarging the specified area.
Additionally, another problem is that the target sometimes goes away from the enlarging display immediately, depending on the relative motion between the target and the ship.
The present invention provides an image monitoring radar apparatus by which users can supervise the predetermined target easily by the enlarging display without complicated operations.
The present invention provides a radar apparatus for displaying target objects on a screen of an indicator, having a means for detect/trail to detect and trail each target location, by detecting the location of multiple targets from the data obtained by the radar apparatus, and detecting the relative quantities of motion from the relative position changes from the ship. The present invention also has a means for specifying the target, which specifies the required target among the targets under the means for detect/trail and has a means for enlargingly display to enlarge the display area in which the targets exists, specified by the means for specifying.
The present invention makes it possible to supervise the target and its surrounding area easily by the simple method of previously selecting the predetermined target among the two or more targets.
Moreover, the present invention can enlargingly display the area, centering the position of the above-specified target.
Thereby, the predetermined range of the circumference is enlargingly displayed, centering the position of specified target.
Moreover, the present invention can periodically update the position of a target specified by a target specification means by detecting and trailing by the means for detect/trail. Therefore, it""s possible to enlargingly display the range of the target and its circumference all the time, even if the target relatively changes the position against the ship.
Moreover, the present invention comprises the means to fix the enlarging area until the target arrives at the end of the enlarged displayarea, and to change the enlarged area so that the pre-specified target will be displayed far from the end of the display when the target arrives at the end of the above-mentioned enlarging area.
The present invention can detect the relative motion of the target which is enlargingly displayed and prevents the target from overflowing an enlarging display part.